Adaptive Coded Modulation for IM/DD Free-Space Optical Backhauling: A Probabilistic Shaping Approach
Type
ArticleAuthors
Elzanaty, Ahmed
Alouini, Mohamed-Slim

KAUST Department
Communication Theory LabComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
Date
2020-07-10Preprint Posting Date
2020-05-05Online Publication Date
2020-07-10Print Publication Date
2020-10Submitted Date
2020-05-05Permanent link to this record
http://hdl.handle.net/10754/662990
Metadata
Show full item recordAbstract
In this paper, we propose a practical adaptive coding modulation scheme to approach the capacity of free-space optical (FSO) channels with intensity modulation/direct detection based on probabilistic shaping. The encoder efficiently adapts the transmission rate to the signal-to-noise ratio, accounting for the fading induced by the atmospheric turbulence. The transponder can support an arbitrarily large number of transmission modes using a low complexity channel encoder with a small set of supported rates. Hence, it can provide a solution for FSO backhauling in terrestrial and satellite communication systems to achieve higher spectral efficiency. We propose two algorithms to determine the capacity and capacity-achieving distribution of the scheme with unipolar M-ary pulse amplitude modulation (M-PAM) signaling. Then, the signal constellation is probabilistically shaped according to the optimal distribution, and the shaped signal is channel encoded by an efficient binary forward error correction scheme. Extensive numerical results and simulations are provided to evaluate the performance. The proposed scheme yields a rate close to the tightest lower bound on the capacity of FSO channels. For instance, the coded modulator operates within 0:2 dB from the M-PAM capacity, and it outperforms uniform signaling with more than 1:7 dB, at a transmission rate of 3 bits per channel use.Citation
Elzanaty, A., & Alouini, M.-S. (2020). Adaptive Coded Modulation for IM/DD Free-Space Optical Backhauling: A Probabilistic Shaping Approach. IEEE Transactions on Communications, 1–1. doi:10.1109/tcomm.2020.3006575arXiv
2005.02129Additional Links
https://ieeexplore.ieee.org/document/9138713/https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9138713
ae974a485f413a2113503eed53cd6c53
10.1109/TCOMM.2020.3006575